Research to be conducted during the coming year calls for continuation of ongoing work on catabolite repression and cyclic AMP in bacteria, and the extension of this program to the regulation of morphogenesis. 1) Work on the regulationof the adenyl cyclase of E. coli will be continued. 2) An attempt will be made to test the hypothesis that different operons and cistrons in E. coli which are controlled by catabolite repression, respond differentially to threshold concentrations of cyclic AMP. This investigation requires certain multiple mutants (devoid of cyclic AMP phosphodiesterase, adenyl cyclase, constitutive for several operons, etc.). 3) The investigation of the role of starvation for carbon in the development of D. discoideum and the role of cyclic AMP therein will be pursued in depth.